jQuery Grid Plugin - jqGrid

A very small thing, but annoying:

I cannot get the rownum-selector in the pager styled like the rest of the grid…in Oleg's demo's I see that on hover the backgroundcolour of the select-drop-down changes to lightblue (redmond). 

In my grid nothing happens on hover over the ui-pg-selbox…and click shows dropdown, but style is not

redmond…

<%= Html.IncludeCSS("redmond/jquery-ui-1.10.3.custom.css")%>

<%= Html.IncludeCSS("ui.jqgrid.css")%>   

<%= Html.IncludeCSS("ui.multiselect.css")%>

<%= Html.IncludeCSS("searchFilter.css")%>

any ideas? (jqgrid 4.5.4, theme south-street, but tried also redmond from ajax)

thanks i.a.

Marc